package queue;

/**
 * @author lynn
 * @date 18-12-14 上午5:49
 */
public interface Queue<E> {

    /**
     * get queue size
     * @return
     */
    int getSize();

    /**
     * get queue is empty or not
     * @return
     */
    boolean isEmpty();

    /**
     * put an element to the queue
     * @param e
     */
    void enqueue(E e);

    /**
     * delete an element from the queue
     * @return
     */
    E dequeue();

    /**
     * get an element from the queue
      * @return
     */
    E getFront();
}
